JP5044481B2 - Structure of fixing portion of antenna element and fixing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure of a portion for fixing an antenna element certainly fixed to provide high reliability by breaking, a pointed portion in each of right and left two ribs inside an arm, into a peripheral wall of the antenna element corresponding to each of the pointed portions. <P>SOLUTION: In each of inner surfaces of right and left walls on a tube wall of the boom, the two ribs elongated in an axis-line direction of the boom are juxtaposed in such a manner as to vertically form a gap therebetween. Each of cross-sectional forms of the two ribs is formed in a chevron-shape. A diameter of a hole of the tube wall is formed larger than a gap between ridge lines of the right and left two ribs. Besides, the ridge line of the rib is cut out at a position where the hole of each tube wall is provided. Eight pointed portions in the right and left two ribs are allowed to be broken into the peripheral wall of an antenna element corresponding to each of the pointed portions. The antenna element is fixed to the boom with antenna's turning and axial motions blocked by the eight pointed portions. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  In the present invention, for example, when transmitting and receiving UHF and other communication signals, a hollow tubular boom is provided with a pair of through holes, and a pipe-shaped antenna element is passed through the through holes. It is related with the structure of the fixing | fixed part of the antenna element fixed by (3), and its fixing method.

Conventionally, a structure and a fixing method of an antenna element fixing portion in which a hollow tubular boom is provided with a pair of through holes and a pipe-like antenna element is fixed to the through holes. It is widely known (for example, see Patent Document 1). For example, the antenna element fixing method disclosed in Patent Document 1 is as follows.
In the tube of the hollow tubular boom, plate-like ribs extending in the axial direction of the boom are provided at the upper and lower side positions of the antenna element in the middle of the cross-sectional position of the antenna element. Next, let the antenna element penetrate the tube wall hole of the boom,
By applying pressure from above and below to the outer wall of the hollow tubular boom to bring the outer walls of the hollow tubular boom closer to each other, and bringing the outer walls of the hollow tubular boom closer to each other, a linear shape is formed in the axial direction in the boom tube. The free end of the rib is pressed against the tube wall of the hollow tubular antenna element and fixed.

Japanese Patent No. 4064836

In this conventional antenna element fixing method,
When the boom is deformed, the antenna element's peripheral wall is pressed with a linear rib that is long in the axial direction of the boom, so if the presser amount is slightly insufficient, the rib against the antenna element's peripheral wall is caused by springback from the antenna element's peripheral wall. The presser foot becomes unstable, and there is a problem that the antenna element is not sufficiently prevented from being pulled out and prevented from rotating with respect to the boom and the reliability is lacking.

  In order to solve the above problems, means for locally pressing and deforming the outer periphery of the boom to fix the antenna element at the locally deformed portion of the boom is also provided. However, when the outer periphery of the boom is locally deformed by pressure, there has been a problem of corrosion from the locally deformed portion.

The purpose of the present application is to allow the antenna element to pass through the boom through-hole, as well as to fix the antenna element to the boom. Thus, an object of the present invention is to provide a structure of an antenna element fixing portion and a method for fixing the antenna element, which can fix the antenna element to the boom very simply by pressurizing the boom in the vertical direction.
Another purpose is to prevent the antenna element from slipping out of the boom by causing the eight pointed heads of the left and right ribs in the boom to bite into the peripheral walls of the corresponding antenna element when the boom is deformed. It is an object of the present invention to provide a structure of an antenna element fixing portion that can be used with a long service life and a fixing method thereof.
Other objects and advantages will be readily apparent from the drawings and the following description associated therewith.

  The structure of the fixing portion of the antenna element according to the present invention is such that the hollow tubular antenna element 20 is passed through the pair of tube wall holes 13 provided in the tube wall 4 of the hollow tubular boom 3, and the antenna element is provided. In the antenna fixed to the boom 3, a gap S is formed between the inner surfaces of the left and right wall portions 4b, 4d, 4f, and 4h of the tube wall 4 of the boom 3 in the vertical direction. Two ribs 8 and 8 which are long in the axial direction of the boom 3 are arranged side by side in the state, and the cross-sectional shapes of the two ribs 8 and 8 respectively arranged on the inner surfaces of the left and right walls are opposite to each other in the left and right direction. It is formed in a mountain shape so that the top portion 11 is formed on the side close to the rib 8. On the other hand, the diameter D1 of the tube wall hole 13 is between the top portions 11 of the left and right ribs 8, 8. The hollow boom 3 is formed larger than the gap S. The antenna element 20 is fixed to the eight ribs 14, 14... 14 formed at the top of each of the four ribs with respect to the tube wall hole 13. .. Which are bitten into the peripheral wall 20a and have the above-mentioned eight pointed heads 14, 14,..., 14 so as to prevent the antenna element 20 from rotating and moving in the axial direction. The antenna element 20 is fixed to the boom 3.

In the antenna element fixing method according to the present invention, the tube wall 4 of the hollow tubular boom 3 has two pairs of tube wall holes 13 and 13 for allowing the hollow tubular antenna element 20 to penetrate in the left-right direction of the boom 3. A hollow tubular antenna element 20 is passed through the pair of tube wall holes 13, 13, and the boom 3 is deformed by applying pressure to the boom 3. In the fixing method of the antenna element in which 20 is fixed, a gap S is formed between the inner surfaces of the left and right wall portions 4b, 4d, 4f, and 4h of the tube wall 4 of the boom 3 in the vertical direction. In this state, two ribs 8 and 8 that are long in the axial direction of the boom 3 are juxtaposed, and the cross-sectional shapes of the two ribs 8 and 8 respectively arranged on the inner surfaces of the left and right walls are opposite to each other in the left and right direction. On the side near the rib 8 11 is formed to the chevron shape so formed,
On the other hand, the diameter D1 of the tube wall hole 13 is formed larger than the gap S between the top portions 11 of the left and right ribs 8 and 8, and by pressing the boom 3 in the vertical direction,
The upper and lower walls 4a and 4e of the tube wall 4 of the boom 3 are deformed in a direction to approach each other, and the left and right walls 4c and 4g are deformed so as to be far away from each other. The ribs are displaced so that the upper and lower apexes approach each other, and by the displacement of the respective ribs, the eight pointed heads formed at the positions corresponding to the tube wall holes 13 at the apexes 11 and 11 of the four ribs. 14, 14... 14, respectively, bite into the peripheral wall 20 a of the corresponding antenna element 20, and the rotation and the axial direction of the antenna element 20 with the above eight pointed heads 14, 14. It is intended to prevent the movement of.

As described above, according to the first aspect of the present invention, the antenna element 20 is fixed to the boom 3 in the eight pointed heads 14 in the left and right ribs 8, 8, 8, 8 in the boom. 14... 14 is in a state of being bitten into the peripheral wall 20a of the corresponding antenna element,
The fixing of the antenna element has a reliable and reliable quality effect.

  In addition, according to the present invention, the antenna element fixing portion with respect to the boom is configured such that the pointed heads 14, 14... 14 of the ribs in the tube wall of the boom 3 are positioned in the tube wall of the boom 3. Since it is fixed by biting into the peripheral wall 20a, the fixed portion is protected from the outside by the tube wall of the boom 3, so that there is an effect that it can be used with a long life while preventing corrosion from the outside.

  Furthermore, according to claim 2 of the present invention, when the antenna element 20 is fixed to the boom 3, the antenna element 20 is passed through the tube wall hole 13 of the boom, and the boom 3 is simply pressurized in the vertical direction. The upper and lower walls 4a and 4e in the tube wall 4 of the boom 3 are deformed in a direction to approach each other, and the left and right walls 4c and 4g are deformed so as to be far away from each other. The two ribs 8, 8, 8, 8 can also be displaced so that the top and bottom of the ribs approach each other so that they can bite into the peripheral wall 20 a of the antenna element 20. There is an effect on the work that can be fixed to.

Embodiments of the present invention will be described below with reference to the drawings.
In FIG. 1, A shows an antenna, for example, a known antenna used for transmission / reception of a known UHF wave. In the antenna A, 3 is a hollow tubular boom, 19 is a director, 25 is a radiator, and 26 is a reflector, which is attached to the boom 3. In the director 19, 20 is an arbitrary plurality of hollow tubular antenna elements that are fixed in a state of penetrating two pairs of tube wall holes 13 in a direction orthogonal to the axis of the boom 3. Yes.
In this field, the antenna is often used with the antenna element protruding left and right with respect to the boom 3 in the state shown in FIG. However, it may be used with the antenna element facing up and down. Therefore, those skilled in the art change the names of the top, bottom, left, and right depending on the form of use. For this reason (in the claims, description, drawings) in this case, in terms of how to use the terms “up”, “down”, “left”, and “left”, it is assumed that they are used in the state shown in FIG. Will be referred to as “upper and lower” as it is.

Next, the structure relevant to the structure of the fixing part of the antenna element 20 with respect to the boom 3 is demonstrated. 2 to 6 show a state before the boom tube wall 4 is deformed.
As is well known, the boom 3 is made of aluminum or a hard material that can be plastically deformed. The cross-sectional shape of the tube wall 4 of the boom 3 is a polygonal shape surrounded by the wall portions 4a to 4h ′ (first wall portion to twelfth wall portion) shown in FIGS. The dimension S1 between 4a and 4e is set larger than the dimension S2 between the left and right wall portions 4c and 4g.

The left and right wall portions (left third wall portion 4b ', left fifth wall portion 4d', right first wall portion 4h ', right side ninth wall) of the tube wall 4 of the boom 3 shown in FIGS. Two ribs 8 that are long in the axial direction of the boom 3 are juxtaposed on each inner surface of the wall portion 4f ′) in a state in which a gap S is formed between them in the vertical direction. The base portion 12 attached to the rib 8 is integrally formed with the tube wall 4 by an integral material, and reinforces the thickness of each corresponding wall portion. Reference numeral 11 denotes a top portion of the rib 8 formed by the first slope 9 and the second slope 10. The cross-sectional shape of the rib 8 is formed in a mountain shape so that the top portion 11 is formed on the side close to the rib 8 facing each other in the left-right direction.
In this way, the boom 3 having four ribs on the inner surface can be manufactured by extrusion as is generally known.

Next, means for fixing the antenna element 20 will be described.
First, with respect to the tube wall 4 of the hollow tubular boom 3 of FIGS. 1 to 5, a pair of two antennas 20 for penetrating a plurality of hollow tubular antenna elements 20 in the left-right direction of the boom 3 using known means. A plurality of perforations are formed in the tube wall hole 13 at a predetermined interval.
As is well known, the diameter D1 of the tube wall hole 13 has a corresponding dimension so that the outer diameter D2 of the antenna element 20 can be inserted, and the top portion 11 is also felt as the ridgeline of the two ribs 8 and 8 on the left and right. 11 (hereinafter also referred to as ridge lines). When the tube wall hole 13 is formed, as shown in FIGS. 3 to 5, the first inclined surface 9 side and the second inclined surface 10 side of each rib are partially scraped, and there is an arcuate attachment surface 16. Are formed respectively. Furthermore, the ridgelines 11, 11 of the two ribs on the left and right in the boom 3 are respectively connected to the through-holes 13 at the positions where the tube wall holes 13 are provided, where continuity is blocked. At the position where the ridge line 11 corresponds to the through hole 13, two (8 in total) pointed heads 14, 14 are provided for each rib by the first inclined surface 9, the second inclined surface 10 and the attached surface 16 of the rib 8. Is formed. As shown in FIG. 4, the space between the pointed heads 14, 14 is smaller than the diameter D <b> 1 of the tube wall hole 13. In addition, the above-described interval is set to such a distance that deformation of the tube wall by the cusps 14 and 14 does not interfere with each other.
In addition, the cross-sectional shape of the rib 8 should just be a shape in which the two pointed heads 14 and 14 are formed by the tube wall hole 13, for example, as shown by a continuous line in FIG. One inclined surface 9 may be parallel to the axis of the antenna element 20, or the first inclined surface 9 may be inclined inward and outward as indicated by a one-dot chain line or a two-dot chain line.
Next, the hollow tubular antenna element 20 is passed through the pair of tube wall holes 13 and 13 as usual. In this state, the antenna element 20 is supported by the two upper and lower attachment surfaces 16 and 16 and the four pointed heads 14 on the left and right ribs as shown in FIGS.

Next, by pressing the boom 3 in FIG. 6 in the vertical direction, the boom 3 is deformed as shown in FIG. 8, and the ribs 8, 8, 8, and 8 in the boom also have upper and lower ridge lines due to the deformation. The antenna elements 20 are displaced so as to approach each other and bite into the peripheral wall 20a of the antenna element 20.
In this regard, the operation of each of the tube wall 4 of the boom 3, the rib 8 in the boom, and the antenna element 20 positioned in the boom 3 will be sequentially described in detail below with reference to FIGS.
6 and 7 show the state of the boom 3 before deformation, FIG. 6 is a sectional view taken along the line AA in FIG. 2, FIG. 7A is a sectional view taken along the line BB in FIG. (B) is the CC sectional view taken on the line of FIG. 8 to 10 show the state of the boom 3 after deformation, FIG. 8 is a sectional view taken along the line AA in FIG. 2, FIG. 9A is a sectional view taken along the line BB in FIG. ) Shows a cross-sectional view taken along the line CC of FIG. FIG. 10 is a cross-sectional view taken along the line XX of FIG. FIG. 11 shows an operation diagram of the walls and ribs in which the outlines of the part G1 in FIG. 6 and the part G2 in FIG. 8 are overlapped.
FIG. 11 is a diagram illustrating a state of the antenna element 20 after the antenna element 20 is fixed to the boom 3.

First, operations related to the operation of the tube wall 4 of the boom 3 are as follows. By pressing the boom 3 shown in FIG. 6 in the vertical direction, the upper and lower wall portions 4a and 4e of the tube wall 4 of the boom 3 are deformed in a direction approaching each other as shown in FIGS. The walls 4c and 4g are deformed so as to be far away from each other. As a means for this deformation, for example, molds 30 and 30 whose cross-sectional shape is shown in FIG. 6 are used. A pair of press dies 30, 30 are arranged with the boom 3 in the middle and facing each other. Reference numeral 30c in the mold 30 denotes a recess having a shape corresponding to the outer peripheral shape of the boom 3 to be finished (the outer peripheral shape of the boom in FIG. 8) on the inner surface of the mold. (Note that the length in the longitudinal direction of the molds 30 and 30 (same as the axial direction of the boom) may be such that a plurality of antenna elements 20 can be fixed simultaneously.)
In the state of FIG. 6, the upper and lower press dies 30, 30 are brought close to arrows 35, 36, respectively. Then, the upper first wall part 4a and the lower fifth wall part 4e are moved by the press molds 30 and 30 toward each other (arrows 35 and 36 directions). Along with this movement, the left fourth wall portion 4c and the right tenth wall portion 4g spread in directions away from each other (directions of arrows 37 and 38). When the left and right wall portions 4c and 4g expand, this is thinner than the portion (4b ', 4d', 4h ', 4f') where the ribs on both sides exist as shown in the figure, or the presence of the tube wall hole 13 The bending strength is weakened, and each of the wall portions is deformed into a bulge shape as shown in the figure, with the center position in the vertical direction as the apex. With such movement of the upper and lower wall portions 4a and 4e and the movement of the left and right wall portions 4c and 4g, the upper left wall portion 4b and the upper right wall portion 4h spread in a square shape, and the lower left wall portion 4d. The lower right wall 4f spreads in an inverted C shape.
As a result, the shape of the tube wall 4 of the boom 3 is deformed into a shape as shown in FIG. Due to this deformation, the upper and lower first, sixth corners 5a, 5f, third, fourth corners 5c, 5d of the corners of the boom tube wall 4 are greatly expanded as shown in FIGS. The angles of the left and right second and fifth corner portions 5b and 5e become smaller as shown in FIGS. By reducing the pressure by pressing up and down in this way, the cross-sectional shape of the boom 3 is approximately the same as the dimension S3 between the upper and lower wall parts 4a and 4e and the dimension S4 between the left and right wall parts 4c and 4g. , Looks better and increases the value of the product. It should be noted that the substantially same dimensions may be approximate as long as they are viewed from an appropriate distance, for example, when the outer shape of the boom is viewed from a place away from about 2 to 3 m, for example, the top, bottom, left, and right appear to be the same dimensions.
In addition, 4j in the pipe wall 4 outer surface of the boom 3 of FIGS.

  Next, the operation of the rib 8 in the boom displaced by the deformation of the tube wall 4 of the boom 3 is as follows. Due to the deformation of the left wall portions 4b and 4b 'and the wall portions 4d and 4d' in the boom pipe wall 4 described above, the left two ribs 8 (8a and 8b) in FIG. 6 are also shown in FIG. In addition, the upper and lower ridgelines 11 are displaced so as to approach each other. Similarly, in the case of the right rib 8 (8c, 8d), the two ribs 8c, 8d are respectively formed by the deformation of the right wall portions 4h, 4h ′ and the wall portions 4f, 4f ′ in FIG. As shown in FIG. 10, the upper and lower ridgelines 11 are displaced so as to approach each other.

By the displacement of the left and right ribs 8a to 8d, the eight pointed heads 14, 14,... 14 and the four attachment surfaces 16, 16, 16, 16 correspond to each other as shown in FIGS. Bite into the peripheral wall 20a of the antenna element 20 to be operated. At this time, the operation of the eight pointed heads 14, 14... 14 formed at the discontinuities of the respective ridgelines 11, 11 in the two ribs 8 on the left and right sides is as follows. is there.
In the state before displacement in FIG. 7B, the two pointed heads 14 and 14 in the two ribs 8c and 8d on the right are in a state along the outer periphery 20b of the antenna element 20 as shown in the figure. It has become. With the displacement of the ribs 8c and 8d, the pointed head 14 is also displaced to the state shown in FIG. 9B.
This movement will be described in detail with reference to FIG. 11 taking one cusp 14 as an example of the cusps in the right rib 8c. As described above, the wall portion 4h, 4h ′ of the tube wall 4 moves from the position indicated by the two-dot chain line to the position indicated by the solid line. Along with this movement, the rib 8c moves in the direction of the arrow 39 and is displaced from the position indicated by the two-dot chain line to the position indicated by the solid line. Along with the displacement, the cusp 14 is also displaced from the position indicated by the two-dot chain line to the position indicated by the solid line, and greatly moves between the distances S5.
Such movement of the cusp 14 can be similarly considered for the other cusp 14 in the right rib 8c. Further, as a matter of course, the two pointed heads 14 and 14 of the right rib 8d also move in contrast to the two pointed heads 14 and 14 of the rib 8c, and the four ribs of the left two ribs 4 The same operation is performed with respect to the four cusps at positions symmetrical to the four cusps in the right two ribs.
In this way, the eight pointed heads 14, 14,... 14 in the two ribs on the left and right are moved simultaneously, and the eight pointed heads 14, 14,. The outer peripheral surface 20b of the antenna element 20 at the corresponding position is pressed and moved while biting into the tube wall 20a of the antenna element 20.

Next, the operation of the four attachment surfaces 16 and the corners 16a formed at the discontinuity of the upper and lower ridgelines 11 and 11 in the left and right two ribs 8 is as follows.
In the state before displacement in FIG. 7A, the upper and lower attachment surfaces 16 and 16 and the corner portions 16a of the right two ribs 8c and 8d are arranged on the outer peripheral surface 20b of the antenna element 20 as shown in the figure. It is in a state along.
When the ribs 8c and 8d are displaced as described above, the attachment surface 16 and its corners 16a are also displaced and the state shown in FIG. 9A is obtained.
This movement will be described in detail with reference to FIG. 11, taking the attachment surface 16 and its corner 16a of the right rib 8c as an example. As described in the operation of the pointed head 14 described above, the rib 8c moves in the direction of the arrow 39 by the movement of the wall portions 4h and 4h 'in the tube wall 4, and the position indicated by the solid line from the position indicated by the two-dot chain line. It is displaced to. Along with the displacement, the attachment surface 16 and the corner 16a are also displaced from the position indicated by the two-dot chain line to the position indicated by the solid line, and moved between the distances S6. This moving distance is small because the attachment surface 16 is farther from the antenna element 20 than the ridge line 11 in the vertical direction. Therefore, the biting into the tube wall is relatively small.
Such movement of the attachment surface 16 and its corner 16a is, of course, the attachment surface 16 of the rib 8d and its corner 16a at the lower right of FIG. The upper and lower attachment surfaces 16 of the left two ribs 8a and 8b and the corner portions 16a thereof also have the upper and lower attachment surfaces 16 and the corners of the right two ribs. The same operation is performed symmetrically with the portion 16a.
In this way, the four attachment surfaces 16 and the corners 16a of the two ribs on the left and right move simultaneously, and at this time, the arc-shaped attachment surfaces 16 corresponding to the outer periphery of the antenna element are respectively in corresponding positions. The outer peripheral surface 20b of a certain antenna element 20 is softly pressed, and the corner portion 16a moves along the tube wall 20a of the antenna element 20 while softly biting.

Next, the deformation of the antenna element 20 is as follows.
As described above, the eight pointed heads 14, 14... 14, the four attachment surfaces 16, and the corners 16 a thereof are in the axial direction of the antenna element 20 (the left-right direction in FIGS. 9 and 12). Displaces while moving. Due to the displacement, the peripheral wall 20a of the antenna element 20 is deformed. The attachment surface 16 and the corner portion 16a of FIG. 9A are deformed along the gentle arc-shaped attachment surface 16, and the vertical dimension D5 is the diameter D2 before deformation (FIG. 7A). ) See) is crushed smaller.
In the portion of the pointed head 14 in FIG. 9B, the left and right sides are deformed as if a wedge is hit from the radial direction to the peripheral wall 20a at the pointed head. The dimension D4 in the vertical direction is crushed even smaller than the portion of the attachment surface 16. Further, the deformation in the lateral direction of the antenna element 20 shown in FIG. 10 is expanded and crushed in the lateral direction more than the portion of the attachment surface 16 (excess by the dimension D6).
These deformations also appear in the plan view after deformation shown in FIG. In FIG. 12, an arrow 41 indicates the moving direction of the attachment surface 16 and the apex 14, 22 is a trajectory of biting due to the displacement of the four apexes in the left and right upper ribs 8 a and 8 c, and 23 is an illustration of FIGS. The ribs 8a and 8c of the ribs 8a and 8c are biting trajectories by the two attached surfaces 16 and 16, 23a is a trajectory of movement, and 23b is a trajectory softly pressed by the attached surface 16.

As described above, by pressing the boom 3 in the vertical direction, the eight pointed heads 14, 14... 14, the four attachment surfaces 16, and their corners 16 a are respectively corresponding antennas. As a result of biting into the peripheral wall 20a of the element 20, the fixing portion of the antenna element in the tube of the boom 3 is in a state as shown in FIGS. In this state, as can be understood from FIGS. 9, 10, and 12, the antenna element 20 was wedged from the radial direction to the peripheral wall 20 a by the eight pointed heads 14, 14. Thus, movement of the antenna element in the axial direction (in the direction of arrow 43 in FIG. 9) is prevented, and rotation in the circumferential direction (in the direction of arrow 44 in FIG. 10) is also reliably prevented.
In addition, the antenna element can be firmly fixed to the boom because it is softly held by the four gentle arc-shaped attachment surfaces 16 in the vicinity of the left and right tube wall hole edges than the pointed head 14. .
In a state where the antenna element 20 is fixed to the boom 4, the portion pressing the peripheral wall 20 a of the antenna element is only a part of the ridge line 11 in the strong rib 8 having a long cross section in the axial direction of the boom and a mountain shape. Since it is pressed by a certain pointed head 14, almost no spring back is generated by the boom, and the biting state of the four pointed heads on the left and right sides of the peripheral wall of the antenna element is maintained, and the fixed state is reliable.

FIG. 13 shows a specific example of the tube wall, the shape and size of the rib on the inner surface of the tube wall, and the size of the tube wall hole in the cross-sectional shape of the boom 3 before and after the deformation. The numbers with parentheses () shown in FIG. 13 are the mutual dimensions (unit: mm) before and after the deformation. Therefore, this number can also be understood as the mutual dimensional ratio of the corresponding parts of the boom 3 before and after deformation. The boom 3 in FIG. 13 was formed using an aluminum alloy (aluminum A6063-T5), and the antenna element (aluminum) having an outer diameter of 8 mm and an inner diameter of 7 mm was used.
Next, FIG. 14 shows the degree of deformation of the tube wall 4 of the boom 3 with respect to the angles of the first corners 5a, 5f, the third corners 5c, 5d of the boom and the second corners 5b, 5e on the left and right. A specific example viewed from the viewpoint of the angle is shown. In FIG. 14, the alternate long and short dash line indicates the outer shape of the boom before pressure deformation, and the solid line indicates the outer shape of the boom before pressure deformation.
As illustrated, in the first corners 5a and 5f and the third corners 5c and 5d, the angle before the deformation was 100 degrees, but after the deformation, it was 120 degrees. The degree of deformation is about 20%. In the second corners 5b and 5e, the angle before the deformation was about 160 degrees, but was 120 degrees after the deformation. The degree of deformation is about 25%.

Next, FIG. 15 which shows an example different in the cross-sectional shape of the tube wall 4 of the boom 3 from the boom of FIGS.
In FIG. 15, parts that are considered to have the same or equivalent configuration in function, property, means, feature, or the like as those in FIGS. 1 to 12 described above are denoted by the same reference numerals as those in FIGS. Description is omitted.
In the boom 3 of FIG. 15, the first wall portion 4a and the fifth wall portion 4e of the tube wall 4 are rounded, and the boom 3 has a substantially elliptical cross-sectional shape. After the deformation, the boom 3 having a shape in which the first wall portion 4a and the fifth wall portion 4e are rounded can be provided.
In this case, the recesses 30f and 30f in the press dies 30d and 30d may be set to a shape corresponding to the outer peripheral shape of the boom 3 to be finished.
Furthermore, in the above description, the relationship between the dimension S1 between the upper and lower wall parts 4a and 4e of the boom 3 and the dimension S2 between the left and right wall parts 4c and 4g is such that dimension S1> dimension S2. , Dimension S1 = dimension S2. In that case, the relationship between the dimension S3 between the upper and lower wall parts 4a and 4e of the boom 3 after deformation and the dimension S4 between the left and right wall parts 4c and 4g is dimension S3 <dimension S4.

The perspective view of an antenna. The left view of the boom before a pipe wall deformation | transformation. It is sectional drawing of the boom before a pipe wall deformation | transformation, (A) is the sectional view on the AA line position of FIG. 2, (B) is the sectional view on the BB line position of FIG. 2, (C) is C-line of FIG. C line position cross section (in addition, the presence of an antenna element is shown with a dashed-dotted line). IV-IV sectional view taken on the line of FIG. The perspective view which fractures | ruptures and shows a part of boom before a pipe wall deformation | transformation. It is sectional drawing in the AA line position of FIG. 2, and is a schematic sectional drawing shown partially broken for demonstrating the fixing method of the antenna element with respect to a boom. FIG. 3 is a schematic cross-sectional view showing a method for fixing the antenna element to the boom, with a part broken away, in which (A) is a cross-sectional view taken along the line AA in FIG. 2, and (B) is a line BB in FIG. Sectional drawing of a position. Sectional drawing in the AA line position in FIG. 2 after a deformation | transformation. (A) is sectional drawing in the BB line position in FIG. 2 after a deformation | transformation, (B) is sectional drawing in the CC line position in FIG. 2 after a deformation | transformation. The XX line position cross section of FIG. 9 (B). The operation | movement figure of the wall part and rib which overlap and show the outline of the code | symbol G1 part of FIG. 6, and the G2 part of FIG. The top view which shows the state of the antenna element after completion of fixation of the antenna element with respect to a boom. (A) is a figure which shows an example of the concrete dimension before and after a deformation | transformation of a boom. Schematic schematic diagram showing the degree of deformation of the boom. Schematic cross-sectional view for explaining examples of different booms (showing a cross-section taken along line BB in FIG. 1).

Explanation of symbols

A ... antenna, 3 ... boom (arm), 4 ... tube wall, 4a ... first wall, 4b ... second wall, 4b '... third wall, 4c ... 4th wall part, 4d '... 5th wall part, 4d ... 6th wall part, 4e ... 7th wall part, 4f ... 8th wall part, 4f' ... -9th wall part, 4g ... 10th wall part, 4h '... 11th wall part, 4h ... 12th wall part, 4j ... fold, 5 (5a-5f) ... Corners, 8 (8a to 8d) ... ribs, 9 ... first slope, 10 ... second slope, 11 ... ridgeline, 13 ... tube wall hole, 14 ... point 16, attached surface 16 a, corner of attached surface, 19, director, 20, antenna element 20 a, tube wall, 20 b, outer periphery, 22, bite mark , 23 ... bite, 23 a ... trajectory of movement, 23 b ... trajectory, 25. Radiator, 26 ... reflector, 30 ... press die, 30c ... recess

Claims (2)

A hollow tubular antenna element is passed through two pairs of tube wall holes provided on the tube wall of the hollow tubular boom, and
In the antenna fixed to the boom, the antenna element is
On each of the inner surfaces of the left and right wall portions of the tube wall of the boom, two ribs that are long in the axial direction of the boom in a state in which a gap is formed between the upper and lower directions are arranged in parallel.
The cross-sectional shape of the two ribs respectively arranged on the inner surfaces of the left and right wall parts is formed in a mountain shape so that the top part is formed on the side close to the opposing ribs in the left and right direction,
On the other hand, the diameter of the tube wall hole is formed larger than the gap between the tops of the two right and left ribs,
The antenna element is fixed to the hollow tubular boom.
Eight pointed heads formed on the top of each of the ribs of the above-mentioned four ribs are made to bite into the peripheral walls of the corresponding antenna elements,
An antenna element for a boom, wherein the antenna element is fixed to the hollow tubular boom with the eight pointed heads so as to prevent the antenna element from rotating and moving in the axial direction. The fixed part structure.
The tube wall of the hollow tubular boom is provided with two pairs of tube wall holes for penetrating the hollow tubular antenna element in the left-right direction of the boom,
A hollow tubular antenna element is passed through the pair of tube wall holes,
By applying pressure to the boom and deforming the boom,
In the antenna element fixing method in which the antenna element is fixed to the boom,
On each of the inner surfaces of the left and right wall portions of the tube wall of the boom, two ribs that are long in the axial direction of the boom in a state in which a gap is formed between the upper and lower directions are arranged in parallel.
The cross-sectional shape of the two ribs respectively arranged on the inner surfaces of the left and right wall parts is formed in a mountain shape so that the top part is formed on the side close to the opposing ribs in the left and right direction,
On the other hand, the diameter of the tube wall hole is formed larger than the gap between the tops of the two right and left ribs,
By pressurizing the boom in the vertical direction,
The upper and lower wall parts of the boom pipe wall are deformed in a direction to approach each other, and the left and right wall parts are deformed to be far away from each other,
By the deformation, the left and right ribs are displaced so that the tops of the top and bottom approach each other,
Due to the displacement of each of the ribs, the eight pointed heads formed at the positions corresponding to the tube wall holes at the tops of the ribs of the four strips are bitten into the peripheral walls of the corresponding antenna elements,
A method of fixing an antenna element, wherein the eight pointed heads prevent the antenna element from rotating and moving in the axial direction.

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